In-line package relay

ABSTRACT

A reed relay wherein the coil and switch terminals are disposed generally in planes parallel to the axis of the relay. A bobbin is molded onto a switch consisting of glass-enclosed contacts with leads projecting therefrom. Coil terminals are molded integrally with the flanges of the bobbin. The coil leads are connected to one side of the terminals which are then bent into notches in the flanges. The switch terminals are formed alternatively by bending them into notches in the bobbin flanges to project at right angles to the axis of the bobbin or by laying a separate terminal in the bobbin and welding the terminals to it. A housing is molded around the bobbin and the respective coil and switch terminals are bent into an in-line position.

This invention relates to a reed relay, and particularly to a reed relayknown in the art as a dual in-line package (DIP), or a single in-linpackage (SIP).

Reed relays in general consist of a pair of contacts encapsulated in aglass envelope with a lead or terminal projecting from each end of theenvelope, this combination forming a switch. The switch is disposed in abobbin about which a coil is wound. The coil leads are connected toterminals. The coil terminals and switch terminals are generally bentdownwardly with respect to the bobbin so as to project at right anglesto the axis of the bobbin at each end of the relay.

The dual in-line package is a reed relay wherein the coil terminals arelocated on one side of the package and the switch leads are located onthe other side of the package as contrasted to the above described relaywhere the terminals and switch leads are located at the end of thepackage. Similarly, the single in-line package has all leads dependingfrom one side of the package. These different lead orientations aredesirable in order to facilitate the mounting of a reed relay on aprinted circuit board and the capability of having leads at differentorientations provides the designer with a certain flexibility as far ashis circuit board design is concerned.

The DIP and SIP relays are known, but the manner of forming them inorder to provide for the proper orientation of the leads has beenexpensive and somewhat laborious. The steps of making the SIP or DIPrelays includes the first step of forming a rectangular frame havingfour transverse straps in the interior of the frame. A combination ofbobbin and switch is positioned adjacent the frame with switch leads incontact with two of the transverse straps, and coil leads are wound onthe other two straps. The coil leads are soldered to their respectivestraps, usually under a microscope. The switch leads are welded to theirrespective straps. While the frame is intact, with the bobbin and switchconnected to it through the soldering and welding operations referredto, a plastic housing is molded around the switch and coil, leaving therespective straps projecting to the sides of a generally elongatedplastic housing. Thereafter, the lead frame is trimmed away from thestraps and the straps are bent downwardly to complete the formation ofthe package. The transverse straps for the switch leads project acrossthe frame and the relay becomes a DIP or SIP depending upon whichportions of the straps are cut away with the remaining portions of thestraps being utilized as connecting points to the circuit board.

An objective of the present invention has been to provide a much moreeconomical SIP or DIP relay. The objective of the invention is attainedin part by the elimination of the lead frame and the expense associatedwith it.

The invention further provides for the formation of a bobbin having thecoil terminals embedded in it so as to project from the side of thebobbin. The coil leads can be wound onto the coil terminals withconventional machinery and very simply soldered by dipping the coilterminals with leads wound thereupon into molten solder. Automaticmachinery either exists or can be simply modified to provide the windingand soldering operations.

The laterally-projecting switch terminals may be formed in one of twoalternative methods. In a first method, the switch leads projecting fromthe glass envelope are bent into notches or transverse slots lying atthe respective ends of the bobbin so as to project as switch terminalsto the side of the bobbin. Alternatively, and without changing thebobbin configuration, a separate switch terminal can be placed in theslots in the ends of the bobbin and the switch leads welded to it. Theswitch terminals project to the side of the bobbin so as to provide thein-line feature.

The thus formed bobbin is thereafter surrounded by a molded plastichousing and the switch terminals and coil terminals bent downwardly toprovide the SIP or DIP configuration.

The bobbin is preferably molded upon the glass envelope so as to encasea small portion of the switch leads projecting from the ends of theenvelope. The switch leads are thus immobilized so that they may be bentwithout concern for the problem of fracturing the joint between theleads and the ends of the glass envelope.

In contrast to the prior method of making the SIP and DIP relays whichutilize the lead frame, the present invention has the followingadvantages:

(a) it minimizes the soldering operations;

(b) the first alternative discussed above eliminates the welding of theswitch leads to the lead frame;

(c) it eliminates the lead frame and the expense attendant to it;

(d) the coil leads are much more easily wound upon their terminals andthereafter soldered;

(e) the coil terminals are better isolated from the switch leads orterminals;

(f) the invention provides the same versatility of lead position as inthe prior method.

The several features of the invention will become more readily apparentfrom the following detailed description taken in conjunction with theaccompanying drawings in which:

FIG. 1 is a diagrammatic illustration of the prior art method of makingSIP or DIP relays;

FIG. 2 is a perspective view of the bobbin and switch assembly of thepresent invention;

FIG. 3 is a side elevational view of the switch assembly;

FIG. 4 is a top plan view of the bobbin and switch assembly beforetrimming the coil terminals;

FIG. 5 is an end elevational view of the bobbin and switch assembly;

FIGS. 6, 7 and 8 are diagrammatic views illustrating the steps ofwinding the coil and connecting it to the coil terminals;

FIG. 9 is a cross-sectional view taken along lines 9--9 of FIG. 8;

FIG. 10 is a diagrammatic plan view illustrating the first alternativefor orienting the switch leads;

FIG. 11 is a diagrammatic plan view illustrating the alternative methodof forming the switch terminals;

FIG. 12 is a plan view illustrating the molding of the housing aroundthe bobbin;

FIG. 13 is a side elevational view illustrating the molding of thehousing around the bobbin;

FIG. 14 is a perspective view of the relay of FIG. 11 illustrating thefinal step in the manufacturing process;

FIG. 15 is a diagrammatic plan view illustrating the application of theinvention to a double pole relay; and

FIG. 16 is a diagrammatic plan view illustrating an alternative form ofapplying the invention to a double pole relay.

The prior art method of forming a DIP or SIP relay is illustrated inFIG. 1. A conductive frame 10 is firm formed. The frame is rectangularand has two straps 11 extending from one side of the frame to the other.The frame also has two L-shaped straps 13 extending generally parallelto the straps 11 but only across a portion of the frame. A bobbin 14having a switch 15 contained in it is juxtaposed with respect to theframe as illustrated. The bobbin has a coil 16 terminating in coil ends17. The ends of the coil are located adjacent the ends of the straps 13.The switch has leads 19 projecting from either end and lying across thestraps 11.

The coil ends 17 are wrapped about the ends of the straps 13 and aresoldered thereto, usually under a microscope. The switch leads arewelded to the straps 11.

To form the SIP, the upper strap portions 11 are trimmed away and ahousing, indicated by broken lines 20, is molded about the bobbin and aportion of the straps. Thereafter, the straps are trimmed away from themain frame and the projecting straps are bent alongside the housing tocomplete the formation of the relay, the straps forming terminals at oneside of the package.

The DIP relay is similarly formed except that the straps 11, as viewedin FIG. 1, are left intact so that the switch lead straps project fromboth sides of the relay and the coil terminals project from one side ofthe relay. The molding and terminal bending operations are againperformed to complete the formation of the relay.

The bobbin and switch assembly of the present invention is illustratedin FIGS. 2 through 5. The bobbin 30 is molded around a glass envelope31, the envelope containing the relay contacts and having switch leads32 projecting from its ends. The molded plastic surrounds a portion ofthe switch leads adjacent the envelope thereby protecting the junctureagainst fracture. The bobbin itself has a cylindrical central portion 34and flanges 35 at each end of the central portion. A U-shaped element 36which ultimately forms the coil terminals has two legs 37 moldedintegrally into the coil flanges, the element 36 projecting from bothsides of the flanges. The free ends 38 of the element 36 projecting toone side are notched as at 39 and are adapted to receive the coil ends.The portion of the element 36 projecting from the other side willultimately form the coil terminals, as will be described.

The flanges are substantially identically formed, there being only aslight difference in configuration to accommodate the location of thecoil leads at the beginning and ending of the coil winding. Each flangehas a coil horn-receiving notch 40, the notch having an inclined surface41 and a transverse surface 42. These surfaces are adapted to receivethe horns or ends 38 of the legs 37 after the coil ends have beensoldered to it. The coil terminals are thus well isolated from theswitch leads. The central portion of each leg 37 of the element 36 isU-shaped, as shown at 44 in FIG. 5, so as to pass by the glass envelope31 and is electrically well isolated from it.

Axially outwardly from the notch 40, each flange is configurated toaccommodate the switch terminal. The configuration includes a pair ofposts 46 on opposite sides of the bobbin, the posts being spaced fromthe main body of the flange to form a notch 47 on each side of thebobbin. A transverse surface 48 lying in a plane passing approximatelythrough the center of the bobbin forms the bottom of the notches 47. Agenerally rectangular boss 50 projects from the end of the flange andextends perpendicularly to the surface 48.

The manner in which the relay is completed after the formation of thebobbin and switch assembly of FIGS. 2-5 is illustrated in FIGS. 6-14.

Referring to FIG. 6, the bight portion 60 of the coil terminal formingelement 36 is trimmed away after molding the bobbin to form coilterminals 63. A coil 61 is wound on the cylindrical portion 34 of thebobbin with leads terminating from each end of the bobbin.

As shown in FIG. 7, the coil leads 62 are wrapped about the projectingends 38 of the element 36 to form the coil horns. The coil horns are dipsoldered and are thereafter bent back into the notch 40 at each end ofthe bobbin 30, as shown in FIG. 8. The orientation of the horns lying onthe inclined surface 41 and the transverse surface 42 is illustrated inFIG. 9.

One method of providing side oriented switch leads or terminals isillustrated in FIG. 10. In that form of the invention, the projectingswitch leads 32 are bent generally at right angles to the axis of thebobbin and into the notch 47 created by the posts 46. If the terminals32 are bent away from the coil terminals 63, the relay will become adual in-line package. Alternatively, the switch leads 32 may be bent inthe opposite direction to lie in the opposed notches 47 to extend on thesame side of the bobbin as the coil terminals 63, thereby forming asingle in-line package. After the switch leads are bent into theposition, the thus formed bobbin is palced in a mold and a housing 66 ismolded around the bobbin, as shown by the phantom lines in FIGS. 12 and13, with the terminals projecting from the housing. The terminals arethereafter bent downwardly to complete the formation of the relay.

In the alternative form of the invention, a U-shaped switchterminal-forming element 70 has legs 71 which are laid in the respectivenotches 47 transversely across the bobbin. Each leg 71 has a U-shapedsection 72 which contacts the switch lead projecting from the ends ofthe bobbin adjacent the rectangular boss 50. The switch leads are weldedto the legs 71 and the axially projecting excess trimmed off.

The thus formed assembly admits of three options for completing therelay. In accordance with the first option, the lower portion of theelement 70, as viewed in FIG. 11, is trimmed away leaving the legs 71projecting in an opposite direction from the coil terminals 63 to form adual in-line package. Alternatively, the upper portion of the legs 71may be trimmed away and only the bight portion of the element 70 trimmedaway so that the switch terminals indicated at 71A project from thebobbin on the same side as the coil terminal 63 to form a single in-linepackage.

The third alternative involves trimming away only the bight portion ofthe element 70 to provide a relay having switch terminals 71 and 71Aprojecting from both sides of the bobbin. The switch terminals on oneside of the bobbin would ultimately be connected into the electricalcircuit, whereas the switch terminals on the opposite side of the bobbinwould be used simply to balance the relay to give it stability when itis mounted to the switchboard or to offer a plurality of connections.

After the switch terminals have been formed on the bobbin in one of thethree alternative methods, a housing is molded to the bobbin and theleads bent downwardly, as described in connection with FIGS. 12-14.

The present invention admits of a double pole relay. In the double polerelay, the bobbin configuration is generally the same as described aboveand the coil and coil horns are formed and laid in their respectivenotches as described above. The bobbin of course is large enough toaccommodate two switches side-by-side with two leads projecting fromeach end of the bobbin.

If the alternative similar to FIG. 10 is employed, the switch leads onboth sides of the bobbin are simply bent into the respective notches sothat the leads for one switch will project from one side of the bobbinand the switch from the other side will project to the other side of thebobbin (FIG. 15). The molding of the housing is performed as describedpreviously.

If the alternative similar to FIG. 11 is employed, a similar U-shapedelement 70 is laid into the notches 47 and across both switch leads ateach end of the bobbin (FIG. 16). The switch leads are welded to thelegs of the element 70 and the small portion 75 of each leg 71 betweenthe adjacent switch leads is trimmed away in order to electricallyisolate the respective switch leads from each other. A housing is moldedto the thus formed assembly and the leads bent as described above.

Having described my invention, I claim:
 1. A reed relay comprising,abobbin having flanges at each end, a glass-encapsulated switch locatedcentrally of said bobbin and having a switch terminal projecting fromeach end, coil terminals embedded in said flanges and projecting from aside of said bobbin at right angles to the axis of said bobbin,transverse notches in said flanges, said switch terminals lying in saidnotches and projecting to a side of said bobbin at right angles to theaxis of said bobbin, and a housing molded around said bobbin, said coiland switch terminals lying in at least one plane parallel to the axis ofsaid bobbin.
 2. A reed relay as in claim 1 in which said switchterminals are formed by bending the switch leads projecting from saidswitch and laying them in said notches.
 3. A reed relay as in claim 1 inwhich said switch terminals are formed by placing terminal-formingelements in said notches, said switch terminals being welded to saidterminal-forming elements projecting from said bobbin.
 4. A reed relayas in claim 1, each said flange having axially inner and outernotches,said coil terminals having free ends connected to coil leads toform coil horns, said coil horns lying in said inner notches, saidswitch terminals lying in said outer notches.
 5. A reed relay as inclaim 1 in which said bobbin is molded around said switch.
 6. A reedrelay comprising,a bobbin having flanges at each end, aglass-encapsulated switch located centrally of said bobbin and having aswitch terminal projecting from each end, coil terminals embedded insaid flanges and projecting from a side of said bobbin and at rightangles to the axis of said bobbin, transverse notches in said flanges,said switch terminals having a right angle bend and being disposed insaid notches to project from a side of said bobbin at generally rightangles to the axis of said bobbin, and a housing molded around saidbobbin, said coil and switch terminals lying in at least one planeparallel to the axis of said bobbin.
 7. In a reed relay including abobbin surrounding two switches each having a terminal projectingtherefrom, coil terminals embedded in said bobbin and a coil wound onsaid bobbin with coil ends soldered to said terminals thereby formingcoil horns, a flange construction at each end of said bobbincomprising,an inner notch adjacent each said coil horn, said coil hornsbeing bent and disposed in said inner notches, an outer transverse notchadjacent each said inner notch, said outer notch adapted to receiveswitch terminals selectively projecting from either side of said flange,a terminal-forming element disposed in the outer notch across theprojecting switch terminals and being welded thereto, the portion ofsaid element between projecting switch terminals being removed toisolate respective switches.
 8. The method of forming a reed relaycomprising the steps of,molding a bobbin having flanges at each end,each flange having inner and outer transverse notches at the side ofsaid bobbin, a transverse coil terminal projecting in oppositedirections from each flange, said coil terminals lying substantially ina plane including the axis of said bobbin, disposing a switch in saidbobbin with said switch having axially projecting terminals, winding acoil on said bobbin, soldering the coil leads to said coil terminals atone side of said bobbin to form coil horns, bending the coil horns intosaid inner notches, and disposing switch terminals in said outer notchesto lie in at least one plane parallel to the axis of said bobbin.
 9. Themethod as in claim 8 further comprising the step of bending said switchterminals into said outer notches to project transversely from saidbobbin,molding a housing around said bobbin.
 10. The method as in claim9 in which said switch terminals project from said bobbin on the sameside as said coil terminals, said switch and coil terminals lying in asingle plane parallel to the axis of said bobbin.
 11. The method as inclaim 8 further comprising the steps of,placing terminal-formingelements in said outer notches extending transversely to said bobbinaxis, electrically connecting said switch terminals to saidterminal-forming elements, and molding a housing around said bobbin. 12.The method of forming a reed relay comprising the steps of,molding abobbin having flanges at each end, each flange having inner and outertransverse notches, a transverse coil terminal projecting in oppositedirections from each flange, a pair of switches disposed in said bobbinand having axially projecting terminals, winding a coil on said bobbin,soldering the coil leads to said coil terminals at one side of saidbobbin to form coil horns, bending the coil horns into said innernotches, placing a terminal-forming element in each of said outernotches, welding said switch terminals to said terminal elements,removing the portion of said terminal-forming element between saidswitch terminals, and molding a housing around said bobbin.
 13. Themethod as in claim 12 further comprising the step of,removing a portionof the terminal-forming element extending to one side of said switchterminal.